General Driver Limits
This section lists various limitations of the UD6/CMtool driver, and where possible, and example of the impact of the limitation.
If a Uniface session unexpectedly terminates DURING a commit or rollback operation, the XML file can effectively be destroyed. Often by careful examination, it can be recovered in a text editor. Fortunately the only reason that Uniface should ever crash DURING a commit or rollback is due to GPF's caused by the driver, which should not happen in regular operation.
Since Uniface is not a multi-threaded application, it only performs a single task at a time, the driver has complete control over execution during these operations. This significantly reduces the risk of a crash occurring and any resultant data loss. If you are particularly concerned about the risk of crashes March Hare advise that you use the UD6/CMtool Driver with Polyserver.
The other reason Uniface may terminate unexpectedly during a commit or rollback operation is user interruption with END TASK or by removing power from the PC or attached network devices.
Internally the driver does not distinguish between filenames and table names that are only different in their ‘case’ (either upper or lower case). Users should therefore avoid using files or tables that are identically named except for the case.
The joins file specifies how the UD6 driver should store several Uniface tables in a single file. This behavior has these limitations:
The UD6 driver has several constants built in for predefined limits. This list is not intended to be definitive, but to give an approximate idea of the limits imposed:
|Problem 1||No LOGO or Advertising Banner|
|Problem 2||Unable to locate 3GL function UDBUD6|
|Problem 3||No response when Assembly Workbench is selected|
|Problem 4||All driver functions slow when used on a shared network drive|
|Problem 5||Transcript shows error 182 - Unable to load DLL.|
|Problem 6||Transcript shows Unable to locate 3GL function UDBUD6.|
|Problem 7||Filenames are sometimes uppercase other times mixed case.|
|Problem 8||DocZilla does not show XML files correctly|
|Problem 9||Internet Explorer 5 gives error when showing XML files|
|Problem 10||9016 - System needs more channels for files. error displayed|
|Problem 11||IDF will not compile components|
|Problem 12||Transcript shows error 31 - Unable to load DLL.|
|Problem 13||XML file exists but IDF cannot find record/form.|
|Problem 14||IE5 incorrectly display XML if USYS$UD6_PARAMS=xsl w3c.|
|Problem 15||Description fields appear in XML file with control characters.|
|Problem 16||Import appears to hang during import of UGLYPH.|
|Problem 17||Edit properties of a label in a component takes a long time.|
|Problem 18||IDF crashes during phase 4 of compile.|
|Problem 19||The process cannot access the file / sharing violation.|
|Problem 20||Cannot find WININET.DLL.|
|Problem 21||1734 - Compiler read error on unexpected empty XXXXXX|
|Problem 22||8069 - Copy failed: Write error on file/table|
|Problem 23||Illegal & character when NLS is off|
|Problem 24||Illegal < character when MHGFP140 is on, garbled bold, underline, and italic text in XML file.|
|Problem 25||-1023 fetch error When UD6 tries to retrieve from user defined table.|
|Problem 26||8080 - Nothing copied. when exporting from UCGROUP.|
|Problem 27||Labels on Paint Tableau have incorrect shape (bold, italic, underline).|
|Problem 28||Cannot import: Commit now! Number of open files preventing open of new file.|
|Limitations||General driver limits|
|$Revision: 1.16 $ $Date: 2015/07/01 05:36:27 $||[go to top]|